/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.datayoo.moql.operand.function;

import java.io.Serializable;
import java.util.concurrent.atomic.AtomicLong;

/**
 * 
 * @author Tang Tadin
 *
 */
public class Counter implements Comparable<Counter>, Serializable {
	private static final long serialVersionUID = 1L;
	
	private AtomicLong count = new AtomicLong();
	
	public Counter(long value) {
		count = new AtomicLong(value);
	}
	
	public void add(long value) {
		count.addAndGet(value);
	}
	
	public synchronized void clear() {
		count = new AtomicLong();
	}
	
	public long getCount() {
		return count.get();
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		// TODO Auto-generated method stub
		return (int)count.intValue();
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#toString()
	 */
	@Override
	public String toString() {
		// TODO Auto-generated method stub
		return String.valueOf(count);
	}

	@Override
	public int compareTo(Counter o) {
		// TODO Auto-generated method stub
		return (int)(count.get() - o.getCount());
	}

}
